• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.29 no.2
• /
• pp.94-108
• /
• 1993

In order to investigate the relation between the environmental properties and catch fluctuation of set net fishing ground located in the coastal waters of Yeosu, oceanographic observation and catches on the grounds were carried out from Jan. to Dec. in 1990 and 1992. The results obtained are summarized as follows; 1) Because of the surveyed area is a costal shallow water, the fishing ground was influenced largely by atmospheric phenomena such as air temperature. precipitation. etc. and so showed large variations in temperature and salinity yearly. The inner water flowed out mainly between Yeosu ad Namhe-do, and then through Kumo-do between Dolsan-do and Kumo-do. On the other hand, off shore water was supplied into the fishing ground from the vicinity of Sori-do and Yokchi-do. thus the fishing ground was occupied usually by various sources of water. 2) The water mass in the fishing ground were divided into the inner water(29.0～30.6$\textperthousand$) and the mixed water(31,7～32.2$\textperthousand$) and off shore water(32.3～32.8$\textperthousand$) accourding to the distribution of salinity from T-S diagram plotted all salinity data observed in 1990 and 1992. In summer the inner and mixing water which was formed by river flowed southerly and spread south-easterly in the vicinity of Kumo-do. The off shore water which supplied from the vicinity of Sori-do and Yokchi-do and inner water formed the thermal front and halo front in summer. 3) The fishes caught by the set net were arranged in the order of catch amounts as follows: Spanish mackerel>Horse mackerel >Hair tail>Common mackerel> Sardine> Anchovy. The Catches of anchovy and sardine were high in April to May and those of hair tail and horse mackerel in July to September, but spanish mackerel were caught during the whole period of fishing. When inner water and mixing water appeared respectively and inner water and mixing water speared together in the set net fishing ground, the set net showed a high catch.

• Journal of Life Science
• /
• v.22 no.1
• /
• pp.1-6
• /
• 2012

The present study examined the effects of consumption of Jeju ground water containing vanadium components on oxidative stress in obese (ob/ob) mice. Intake of Jeju ground water decreased the generation of oxidative stress induced-lipid peroxidation in the liver of ob/ob mice It also enhanced the enzymatic antioxidant defense system by increasing the protein expression and activity of superoxide dismutase, catalase, and glutathione peroxidase in liver tissues. Jeju ground water intake also upregulated the intracellular content of reduced glutathione. The induction of antioxidant enzyme expression by consumption of Jeju ground water was mediated by the erythroid transcription factor NF-E2 (Nrf2). Increased nuclear expression of phospho Nrf2 was observed in ob/ob mouse liver cells following ntake of Jeju ground water. These results suggest that consumption of Jeju ground water stimulated the antioxidant defense system in the livers of ob/ob mice via induction of Nrf2.

• Geotechnical Engineering
• /
• v.12 no.5
• /
• pp.5-16
• /
• 1996

When braced excavation with temporary retaining wall installation, is performed in loose sand with high ground water level boiling may be induced and considerable damage on the excavation works and structures in the vicinity can take place. Recently, for the purpose of reinforcement of ground and cut-off of ground water behind the temporary retaining wall, high pressure jet grouting is widely used. The purpose of this paper is to investigate the effects of jet grouting on ground reinforcement and cut -off of the ground water behind temporary retaining walls for braced excavation. A series of both laboratory and field tests has been performed. The test results show that high pressure jet grouting has sufficient effects on reinforcement of stiffness of ground and retaining wall. The permeability of the improved ground was 10-f_ 10-3cm l s smaller than those of the original ground. Therefore, the effect on cut off of ground water behind temporary retaining walls could be improved by high pressure jet grouting method.

• Economic and Environmental Geology
• /
• v.11 no.3
• /
• pp.99-108
• /
• 1978

The Gum-Ho river basin is one of the densely populated area having more than 35% of the total population and it was also well irrigated since earlier days in the Nackdong river basin. Most of the easily developed source of surface water are fully utilized, and at this moment the basin is at the stage that no more :surface water can be made available under the present rapid development of economic condition. Since surface water supplies from the basin have become more difficult to obtain, the ground water resources must be thoroughly investigated and utilized greatly hereafter. In economic ground of the basin what part could ground water play? In what quantities and, for what uses could it be put? The answer to these questions can be relatively simple;the ground water resources in the basin can be put at almost any desired use and almost anywhere in the basin The area of the basin is at about $2088km^2$ in the middle part of Nackdong river basin and it is located along the Seoul-Pusan express highway. The mean annual rainfall is about 974.7mm, most of which falls from June to September during the monsoon. Accumulated is appeared approximately after every 8 year's accumlated dry period with the duration of 5 years. The water bearing formation in the basin include unconsolidated alluvial deposits in Age of Quaternary, saprolite derived from weathered crystalline rocks, Gyongsang sedimentary formations of the period from late Jurassic to Cretaceouse, and igneouse rocks ranging of the Age from Mesozoic to Cenozoic. The most productive ground water reservoir in the basin is calcareous shale and sandstones of Gyongsang system, which occupies about 66% of the total area. The results of aquifer test on Gyongsang sedimentary formation show that average pumping capacity of a well drilled into the formation with drilling diameter and average depth of $8{\frac{1}{2}}$ inch and 136m is $738m^3/day$ and also average specific capacity of those well is estimated $77.8m^3/D/M$. Total amount of the ground water reserved in the basin is approximately estimated at 37 billion metric tons, being equivalent 18 years total precipitations, among which 7 billion metric tons of portable ground water can be easily utilized in depth of 200 meters.

• Water for future
• /
• v.12 no.1
• /
• pp.21-27
• /
• 1979

Ground water stored in the alluvium and the rocks provides the vase flow of the streams and can be withdraw from wells and infiltration galleries. And it is also recharge naturallyby precipitation. The amount of ground water in the four major basins it is estimated to be about 137,000 million cubiv meters(Table1), while nationwide ground water storage to be about 232,000 million cubic meters. The estimation of storage volume has been made on the basis of assumed thickness of the saturated zone of the different rocks and assumed porosities of those rocks. The values of the porosity of alluvium and saprolite were assumed to be 25% and 40% respectivvely which are based on tests made of similar materials in Georgia, U.S. The volume of water in storage is believed to be a conservative estimate. Detailed geologic and hydrologic investigation should be made where and when water resources are needed.

• Journal of Korean Society on Water Environment
• /
• v.23 no.1
• /
• pp.64-71
• /
• 2007

In this study daily flow data is constructed from 8-day intervals flow data which has been measured by Nakdong River Water Environmental Laboratory. TANK model is used to expand 8-day intervals flow data into daily flow data. Using the Sequential quadratic programing, TANK model is auto-calibrated with daily precipitation and 8-day interval flow data. Generated and measured daily surface flow, ground water flow data and ground water recharge are shown to be in a good agreement. From this result, it is thought that this method has the potential to provide daily flow data for calibrating an watershed model such as SWAT.

• Proceedings of the SAREK Conference
• /
• 2008.06a
• /
• pp.769-775
• /
• 2008

The objective of this report is to determine the difference of thermal response that grouted two different materials, and compare the simulation result of the length of total ground heat exchanger length that using the ground thermal conductivity. And also to know heat exchange variation of ground heat exchanger temperature that measured with various test depth. The result shows that the test hole grouted with water permeable material got better thermal response than grouted with water impermeable material. However, with consideration of ingnore for the initial 12 hour data, the test hole grouted with impermeable material has larger thermal conductivity than the other. By former thermal conductivity, simulated data by engineering program shows only 3.4% difference or less. This result shows that ground thermal conductivity is not the main variables for the design program of ground heat exchanger. At the cooling or heating mode, base on the depth of -150m, the ground heat exchanger has best temperature at $-90{\sim}-60m$ and than getting worse because of entering water heat exchanged with leaving water in the same hole.

• Journal of Soil and Groundwater Environment
• /
• v.16 no.2
• /
• pp.1-5
• /
• 2011

We surveyed the citizens opinion about springs in Seoul for two years from 2008 to 2009. It was found that spring water was mostly used by citizens older than 50, and that 29.5% of citizens used purified tap water as drinking water, 27.2% of them used boiled tap water, 21.1% of them used spring water, and 12.1% of them used bottled water. Citizens who store spring water more than a day are 76.7%. Although many citizens (70.3%) knew that water quality had been tested, 40% of them didn't care about checking the certificate of water quality analysis. Once recognized that the spring water was unfit for drinking exceeded standard of drinking water, 85% of citizens would rather not use the spring water.

• Journal of Korean Society of Water and Wastewater
• /
• v.22 no.3
• /
• pp.307-314
• /
• 2008

In this study, the effects of applied voltage, solution pH and coexistence of other ions such as sulfate ion (${SO_4}^{2-}$) and chloride ion ($Cl^-$) were investigated on the removal of nitrate-nitrogen ($NO_3{^-}-N$) from ground water by electrodialysis. The examined operating conditions were evaluated for optimizing the removal efficiency of $NO_3{^-}-N$. Real ground water samples taken from a rural area of Yongin city and artificial ones with components similar to the real ground water were tested for the study, which contained $NO_3{^-}-N$ concentration of 17mg/L that exceeds current drinking water quality standard of 10 mg/L. The increase in the removal rate of $NO_3{^-}-N$ was observed as the applied voltage increased from 5V to 30V, while no significant increase in the removal rate appeared at the applied voltage beyond 20V during a given operating time. The removal rate appeared to get lower at both acidic and basic condition, compared to neutral pH. Coexistence of of ${SO_4}^{2-}$and $Cl^-$ demanded much longer operating time to achieve a given removal rate or to meet a certain level of treated water concentration. When nitrate ion was combined with ${SO_4}^{2-}$and $Cl^-$, the removal rate was reduced by 4.29% and 10.83%, respectively.

• Analytical Science and Technology
• /
• v.16 no.1
• /
• pp.59-69
• /
• 2003

Benzophenone (BZP) and 4-nitrotoluene (4-NT) listed as endocrine disrupting chemicals are suspected to contaminate ground water sites and soil. Analytical method for simultaneous determination of the two chemicals in soil and ground water was developed by gas chromatography-mass spectrometry. Water (100 ml) was extracted with hexane, and soil (10 g) was extracted with methanol and hexane. Recovery in water was >72% for BZP and 90-118% for 4-NT. Recovery for 4-NT and BZP in soil was 51-59% with coefficient variation of less than 19.5%. Calibration curves showed a good linearity with $r^2=0.997$. In water and soil collected at nation-wide sites, BZP was found at 5 sites among 43 water sites at the concentration of $14.87{\pm}3.83ng/100 ml$. No 4-NT was found. It is suggested that this method is appropriate to the simultaneous quantitation of 4-NT and BZP in ground water and soil samples.